tests: fix strace--tips test

Apparently, it has been broken in many places and checked the output
incorrectly, so it was basically useless.  Make it a bit less broken
by properly escaping all the regular expressions and implement the logic
that actually checks the output against the expected patterns.

* tests/strace--tips.test (IFS): Set the variable to avoid stripping
whitespace from the read lines.
(grep_ere_escape): A variant of sed_re_escape that also escapes "{",
"}", and "|" characters.
Add "-r" option to the read call to avoid interpreting backslashes,
especially at the end of the line;  escape "|", "/", and "\" characters
in $pat/$end/$btm definitions and fix the whitespace usage in there;
use grep_ere_escape instead of sed_re_escape;  break after matching one
last line against $btm if TIPS_FULL is not set;  pass "-x" option
to the grep calls.

Fixes: v5.18~38 "Raise strace awareness"

1 files changed, 30 insertions, 23 deletions

diff --git a/tests/strace--tips.test b/tests/strace--tips.test
index 7bb89c0d0..328e55fbb 100755
--- a/tests/strace--tips.test
+++ b/tests/strace--tips.test
@@ -6,10 +6,15 @@
 : "${TIPS_FULL:=0}"
 RAND_TIPS=5
 MAX_TIPS=500
-
+IFS='
+'
 tips_fmt_opt=""
 [ 1 -ne "$TIPS_FULL" ] || tips_fmt_opt="--tips=full"
 
+grep_ere_escape()
+{
+	printf "%s" "$*" | sed 's/[].*&^$()|[\/]/\\&/g'
+}
 
 # Check that simple "strace --tips=0" works as expected
 args='--tips=0'
@@ -35,42 +40,44 @@ while [ "$i" -lt "$MAX_TIPS" ]; do
 
 	j=0
 	end_seen=0
-	cat $srcdir/strace--tips.exp | while read line; do
+	cat $srcdir/strace--tips.exp | while read -r line; do
 		j="$((j + 1))"
 		case "$j" in
-		1) pat='  ______________________________________________         '"$(sed_re_escape "$line")";;
-		2) pat=' /                                              \\        '"$(sed_re_escape "$line")";;
-		3) pat=' | .{44} |   '"$(sed_re_escape "$line")";;
-		4) pat=' | .{44} \   '"$(sed_re_escape "$line")";;
-		5) pat=' | .{44}  \  '"$(sed_re_escape "$line")";;
-		6) pat=' | .{44}  _\ '"$(sed_re_escape "$line")";;
-		7) pat=' | .{44} /   '"$(sed_re_escape "$line")";;
-		*) pat=' | .{44} |   '"$(sed_re_escape "$line")";;
+		1) pat='  ______________________________________________    '"$(grep_ere_escape "$line")";;
+		2) pat=' \/                                              \\   '"$(grep_ere_escape "$line")";;
+		3) pat=' \| .{44} \|   '"$(grep_ere_escape "$line")";;
+		4) pat=' \| .{44} \\   '"$(grep_ere_escape "$line")";;
+		5) pat=' \| .{44}  \\  '"$(grep_ere_escape "$line")";;
+		6) pat=' \| .{44}  _\\ '"$(grep_ere_escape "$line")";;
+		7) pat=' \| .{44} \/   '"$(grep_ere_escape "$line")";;
+		*) pat=' \| .{44} \|   '"$(grep_ere_escape "$line")";;
 		esac
-		end=' \______________________________________________/        '"$(sed_re_escape "$line")"
-		btm='                                                         '"$(sed_re_escape "$line")"
+		end=' \\______________________________________________\/   '"$(grep_ere_escape "$line")"
+		btm='                                                    '"$(grep_ere_escape "$line")"
 		s=$(tail -n"+$j" "${OUT}.${i}" | head -n1)
 
 		if [ 0 -ne "$end_seen" ]; then
-			printf '%s' "$s" | grep -Eq "$btm" || \
+			printf '%s' "$s" | grep -Exq "$btm" || \
 				fail_ "Can't match line $j of ${OUT}.${i}" \
 					"('$s') against '$btm'"
+			if [ 0 -ne "$TIPS_FULL" ]; then
+				continue
+			else
+				break
+			fi
 		fi
 
-		printf '%s' "$s" | grep -Eqv "$pat" || continue
-		if [ 8 -lt "$j" ]; then
-			printf '%s' "$s" | grep -Eq "$end" || \
-				fail_ "Can't match line $j of ${OUT}.${i}" \
-					"('$s') against neither '$pat' nor '$end'"
+		if ! printf '%s' "$s" | grep -Exq "$pat"; then
+			if [ 8 -lt "$j" ]; then
+				printf '%s' "$s" | grep -Exq "$end" || \
+					fail_ "Can't match line $j of ${OUT}.${i}" \
+						"('$s') against neither '$pat' nor '$end'"
 
-			if [ 0 -ne "$TIPS_FULL" ]; then
 				end_seen=1
 			else
-				break
+				fail_ "Can't match line $j of ${OUT}.${i} ('$s')" \
+					"against '$pat'"
 			fi
-		else
-			fail_ "Can't match line $j of ${OUT}.${i} ('$s')" \
-				"against '$pat'"
 		fi
 	done